Intravenous regional anesthesia
Stem
A 45-year-old woman, 60 kg, is scheduled for an open carpal tunnel release expected to take 20 minutes. She is healthy, has a blood pressure of 125/75, and wants to avoid general anesthesia and go home the same day. The surgeon asks for a Bier block.
Question
How will you perform intravenous regional anesthesia for her, and what makes it safe?
Ideal answer
HeadlineGood for a short hand case: the tourniquet is its safety, so I check the cuff first and keep it up at least 20 minutes.
- Exclude contraindications. No amide allergy or sickle cell disease; no impaired perfusion, venous thrombosis or open wound there.1
- Small hand catheter, other-arm IV, double cuff, for rescue drugs; standard monitors, tourniquet high on the arm.
- Exsanguinate, inflate proximal cuff 50–100 mm Hg above systolic, to trap the local anesthetic: elevation, Esmarch bandage; no radial pulse.2
- 0.5% preservative-free lidocaine, 3 mg/kg, no epinephrine. 180 mg, 36 mL, slowly over 1–2 minutes, catheter out;3,1 onset 5–10 minutes.1
- Cuff up at least 20 minutes, cycled before 40. Even if surgery ends earlier.1 Tourniquet pain: distal cuff up over anesthetized skin before proximal deflation.2
Watch for: Toxicity after release; lipid emulsion in the room; never bupivacaine.1
Breaking down the answer
- Pick the right case — procedures of an hour or less, such as carpal tunnel release, ganglion excision or fracture reduction; postoperative analgesia is poor unless adjuncts are added.1
- What fails — tourniquet failure, an infiltrated catheter and premature deflation are the things to watch;1 checking the cuff for leaks before injection shows judgment.
- Dose by weight, cap by volume — RCH caps 3 mg/kg at 200 mg or 40 mL;3 OpenAnesthesia cites a lower ceiling of 2.5 mg/kg, my limit for the small or frail.1 A forearm tourniquet allows about half, 1.5 mg/kg.2
- Time before release — no later than 45 minutes per the RCH guideline;3 between 20 and 40 minutes, cycled deflation: deflate 5 seconds, reinflate 1 minute, repeat.1 This meters the lidocaine into the circulation.
- Bupivacaine is contraindicated — its cardiotoxicity risks cardiac arrest once the cuff comes down.1
- Adjuncts — dexmedetomidine 0.5–1 mcg/kg, clonidine, ketorolac or dexamethasone can speed onset, improve tourniquet tolerance or extend analgesia.1
Follow-up question
Twelve minutes after injection the proximal cuff suddenly loses pressure from a tubing leak. She says her ears are ringing and her lips feel numb, then she has a generalized seizure. What do you do?
Follow-up answer
HeadlineLocal anesthetic systemic toxicity from early release of 180 mg of lidocaine; I call for help and the LAST kit: LAST, not epilepsy.
I secure her airway with 100% oxygen and give a benzodiazepine for the seizure; propofol only in small doses if nothing else is available.4 I start 20% lipid emulsion early: about 90 mL over 2–3 minutes, then 0.25 mL/kg/min, about 15 mL/min, repeating the bolus if she stays unstable.4 For hypotension or arrhythmia, epinephrine under 1 mcg/kg; no vasopressin, calcium-channel blockers, beta-blockers or more local anesthetic.4 Rhythm and pressure continuously, and at least 2 hours of observation after the seizure.4
Pitfalls that cost points
- Letting the surgeon release the cuff at 10 minutes because the case is finished.
- Giving the dose in mL without converting from mg/kg.
Rapid-fire
Q: How does the block work? A: Local anesthetic diffuses out of the veins and blocks the nerve endings and small nerves of the exsanguinated limb.1
Q: Which patients are poor candidates? A: Those with crush injuries, compound fractures, arteriovenous shunts, local infection, sickle cell disease or surgery planned for more than an hour.1
Q: Why switch cuffs at 25–30 minutes? A: The distal cuff sits on anesthetized skin, so tourniquet pain is less.2
Q: Can it be used in the leg? A: Yes, with larger volumes because of the larger limb.2
Numbers to know
| Item | Value |
|---|---|
| Lidocaine | 0.5%, 3 mg/kg, max 200 mg or 40 mL3 |
| Proximal cuff | 50–100 mm Hg above systolic2 |
| Onset | 5–10 min1 |
| Minimum cuff time | 20 min after injection3 |
| Cycled deflation | Between 20 and 40 min1 |
| Lipid bolus (<70 kg) | ~1.5 mL/kg over 2–3 min; maximum 12 mL/kg4 |
Links
- Local anesthetic systemic toxicity, Bone cement, tourniquets and hip fracture, Supraclavicular, infraclavicular and axillary blocks, Ambulatory anesthesia and discharge criteria
- ASRA Checklist for Treatment of Local Anesthetic Systemic Toxicity (2020)
Sources
- 1.Intravenous Regional Anesthesia (Bier Block) · OpenAnesthesia · openanesthesia.orgIndications, absolute and relative contraindications, equipment, technique, cycled deflation, complications. Its stated lidocaine ceiling (2.5 mg/kg) is lower than the 3 mg/kg used by NYSORA trials and the RCH guideline.
- 2.Intravenous Regional Block for Upper & Lower Extremity Surgery · NYSORA · nysora.comTechnique (proximal cuff 50-100 mm Hg above systolic, 30-50 mL 0.5% lidocaine), cuff switch at 25-30 min, forearm tourniquet with 1.5 mg/kg lidocaine.
- 3.Bier block (Clinical Practice Guideline) · The Royal Children's Hospital Melbourne, 2020 · rch.org.auLidocaine 0.5% 3 mg/kg (0.6 mL/kg; max 200 mg or 40 mL); do not deflate before 20 or later than 45 minutes.
- 4.Checklist for Treatment of Local Anesthetic Systemic Toxicity (LAST) · ASRA Pain Medicine, 2020 · asra.com
Facts on this page were checked against these sources on Oct 16, 2026. Guidelines change; confirm doses against current institutional protocols.